Real-time PK Measurement of the Chemotherapeutic Drug Melphalan in Whole Blood by a Novel PaperSpray Mass Spectrometry

Transcription

1 Palm Springs, California February Real-time PK Measurement of the Chemotherapeutic Drug Melphalan in Whole Blood by a Novel PaperSpray Mass Spectrometry Junfang Zhao, Chandra Sharat, Parinda A. Mehta, Alexander A. Vinks, Kenneth D.R. Setchell* Cincinnati Children s Hospital Medical Center Nicholas Edward Manicke Indiana University-Purdue University Indianapolis

2 Analyte of Interest: Melphalan Chemotherapeutic drug belongs to the class of nitrogen mustard alkylating agents. Melphalan is commonly used in high doses in the treatment of blood marrow cancer, and hematopoietic stem cell transplantation (HSCT). (MW=305.2) 4-[bis(chloroethyl)amino] phenylalanine Trade name: Alkeran Melphalan has substantial toxicity at high doses, which can be life-threatening. Optimization of the drug dose is critical, especially for pediatric patients: Not too little, not too much just right!

3 Objectives Objects /Aims / Aims To understand the pharmacokinetics (PK) of melphalan in children undergoing HSCT and establish pediatric PK data 1. Develop and validate a rapid novel PaperSpray Tandem Mass Spectrometry (PS-MS/MS) method suitable for measuring melphalan in small samples of blood 2. Compare with our conventional LC-ESI-MS/MS method 3. Investigate and evaluate the feasibility of this novel approach utilized in the clinical setting for real-time PK in order to select appropriate dosage regimen

4 Typical Approach for Drug Analysis by Mass Spectrometry Blood sample storage Blood Sample Collection Protein Precipitation Plasma preparation/isolation Solid Phase Extraction Liquid Liquid Extraction Mass Spectrometry Liquid Chromatography Time-consuming, labor-intensive, not suitable for making real-time dose optimization

5 PaperSpray Mass Spectrometry Blood Sample Collection PaperSpray Sample Cartridge PaperSpray Ion Source Direct analysis of blood samples spotted on paper. Targeted quantitative analysis of drugs and drug metabolites directly from a dried blood spot.

6 Advantages of PaperSpray Simple, no sample pretreatment suitable for real-time analysis No HPLC system or chromatography required No carryover between samples Uses small sample volumes (10 ~ 12 µl blood) Low solvent volumes (100 ~ 200 µl) Rapid analysis (~ 3 min/sample) / Reduced cost Results can be immediately reported to the physician

7 PaperSpray Ionization Extraction/Spray solvent (170 µl) Analyte ion H.V 3 ~ 5 kv 12µL blood containing I.S Paper triangle Inlet to MS He Wang, Jiangjiang Liu, R. Graham Cooks, and Zheng Ouyang. Angewandte Chemie Vol 49, p 877.

8 PaperSpray Method for Melphalan Matrix: Dried blood spots; Dried plasma spots Calibration and QC standards - Prepared in drug free human blood (plasma) - Prepared one set of calibration and QC standards containing melphalan Internal Standard -[ 2 H 8 ]-Melphalan - Internal standard solution was spiked into blood sample prior to spotting PaperSpray-MS/MS - 12 μl of whole blood (10 μl of plasma) was spotted onto the disposable paperspray cartridge and allowed to dry - Analysis was performed using a prototype Prosolia automated paperspray ion source without any additional sample work up - Extraction/spray solvent: Ethanol:Acetone:Trifluoroethanol:H 2 O (40:20:20:20, by Vol) - MS: Thermo TSQ Quantum Ultra

9 CID spectra of Protonated Melphalan and D 8 -Melphalan 100% quantifier % Relative Intensity % Relative Intensity 50% 0% 100% 50% m/z % qualifier ( CO 2 + CH 3 Cl) ( CO 2 + CHD 2 Cl ) 250 ( NH 3 + CH 2 CO) (NH 3 + CH 2 CO) m/z [Mel+H] + [d 8 -Mel+H] + 350

10 PaperSpray Ion Recording for Melphalan and D 8 -Melphalan in Whole Blood

11 Melphalan: Calibration Curve in a Whole Blood Matrix Assay linear over a wide dynamic range of concentrations weighting =1/x

12 PaperSpray Ion Recording for Melphalan in Whole Blood Absolute abundance MRM m/z > m/z > LLOQ = 50 ng/ml Real patient blood Blank (drug free) blood Time (min) Signal for LLOQ (50 ng/ml in DBS) is ~20X greater than blank Signal for LOD (25 ng/ml in DBS) is ~10X greater than blank

13 Melphalan: Intra-day and Inter-day Quality Controls Precision and Accuracy a Precision=100 standard deviation/mean. b Accuracy = % of nominal concentration.

14 Application Study: application of PS-MS/MS methodology to real-time pharmacokinetic study of melphalan in children undergoing HSCT Approved by the CCHMC Investigational Review Board, Protocol # Melphalan

15 Protocol of Melphalan PK Study: Phase 1 Patients 30 children undergoing HSCT : aged< 2 (10), 2 years (10), and regardless of years of age (10). Dose Selection Test dose: 10% of standard dose, administrated by IV over 3-5mins. Standard dose: 140 mg/m 2 for children 10 kg, 70 mg/m 2 for children < 10 kg, administrated by IV over 30mins. Collection Time Points PK Study IV 30mins baseline post min 2hr 2.5hr 4hr 6hr 8hr Real-time PK by PS-MS/MS PK by conventional LC-ESI-MS/MS

16 LC-ESI-MS/MS Method in Use Blood Sample Plasma LC20AD HPLC system (Shimadzu) Calibration curve from 2ng/mL to 1000ng/mL (LLOQ = 2ng/mL) D 8 -Melphalan as internal standard 1/x weighted least squares Protein Precipitation Centrifugation LC-ESI-MS/MS Thermo TSQ Ultra Area Ratio Melphalan\d 8 -melphalan y = x R 2 = concentration (ng/ml)

17 Melphalan Cross Validation blood vs. plasma plasma vs. plasma PS-MS/MS (Blood, ng/ml) y = x R 2 = n = 62 PS-MS/MS (Plasma, ng/ml) y = x R 2 = n = 62 HPLC-MS/MS (Plasma, ng/ml) HPLC-MS/MS (Plasma, ng/ml)

18 Melphalan Pharmacokinetic Behavior LC-ESI/MS/MS (Plasma) PS-MS/MS (Whole blood) Melphalan is eliminated by first-order kinetics

19 Bioavailability: Melphalan AUC (min*mg/ml) Pharmacokinetic analysis: Non-compartment, WinNonlin version 6.4 Trapezoidal area under the curves (AUCs) were calculated. PS-MS/MS (Blood, min*mg/ml) R 2 = HPLC-MS/MS (Plasma, min*mg/ml) ID Full Dose AUC (min*mg/ml) PS-MS/MS (blood) LC-MS/MS (plasma) Test Dose AUC (min*mg/ml) PS-MS/MS (blood) LC-MS/MS (plasma) Mean SD

20 Summary Add I.S. dry Blood sample Spot blood onto paper Load to the PS ion source 1. A simple, accurate and rapid PS-MS/MS method for melphalan in small volume of blood 2. Excellent correlation between PS-MS/MS and LC-ESI-MS/MS 3. PS permits real-time analysis and rapid data reporting for melphalan in pediatric patients, allowing bedside dose adjustment

21 Acknowledgement Prosolia Inc. Thermo Scientific MSACL 2016 Travel Award